Mayo Diet???

Im 15 years old and i think im gonna go on the mayo diet.I am 4'11 tall and i weigh 190(unhealthy)I wear a size 16 in jrs. I want to get down to my goal size which is a size 5 in jrs.Is it possible to get there by Christmas or alittle after??I have a party to go to in the middle of January and my whole family is gonna be there and i want to look good and be confident.I wanna do this for me not anyone else.I also can add in a pilates tape i have for exercise.Can someone give me the info for the mayo diet.Thanks!